BRIEF COMMUNICATION: Development of ultrasound methodology to measure cow udder cistern storage capacity in the New Zealand pasture-fed context

摘要

Studies have demonstrated that, for a given amount of secretory tissue, cows with a proportionally larger cistern produce more milk and are more resistant to the inhibitory effects on milk synthesis of longer milking intervals (Knight & Dewhurst 1994;Stelwagen & Knight 1997; Davis et al. 1998). This may be because they can store more milk before milk accumulation begins to inhibit further milk synthesis. Ayadi et al. (2003) demonstrated in a feedlot situation that cisternal volumes can be measured non-invasively using ultrasound technology. Dairy systems based on pasture, such as those in New Zealand, exhibit different challenges to the production of useful data using this technology compared to feed lot systems and the confounding effect of the variability in milking order and the subsequent variations of the intervals between subsequent milking (Molenaar et al. 2012).